In the floating type brake disc, a disc hub and a friction disc, formed separately, are combined with each other with a very small clearance therebetween. Accordingly, this type of brake disc enjoys an advantage that its braking action does not fluctuate since the friction disc undergoes uniform heat expansion when exposed to the frictional heat generated by braking operation to suffer no strain on the braking surface thereof and further the disc is not constrained by the disc hub.
A prior art floating type brake disc is disclosed, for example, in Japanese Provisional Utility Model Publication No. 46539/1989. In the disclosed brake disc, a plurality of connecting members are formed on the disk hub and friction disc, respectively, and the thickness of each opposing pair of connecting members are reduced to 1/2 so that the thickness of the two connecting members may be 1/2 the thickness of the disc hub and that of the friction disc, respectively. Connection holes having different inner diameters are also formed through these connecting members, respectively, and each pair of connecting members are combined with each other in such a way that the reduced portions may be overlapped and that the connecting holes thereof may communicate to each other. A stepped connecting pin is inserted through the combined connecting holes of the connecting members, and after a washer is fitted to the point of the connecting pin, the point of the pin is caulked. Since the disc hub and the friction disc are thus bound elastically between the head of the connecting pin and the washer, the head of the connecting pin and the washer deflect if the friction disc undergoes heat expansion and can cope with the fluctuation or expansion in the thickness of the friction disc.
However, the above structure suffers a problem that the skill of an expert is required for the caulking operation since the friction disc may not be supported evenly unless the connecting pins are caulked with an equal power, and that it is troublesome to remove the connecting pins when the friction disc is replaced.